Solvent-free preparation of polylactic acid fibers by melt electrospinning using umbrella-like spray head and alleviation of problematic thermal degradation

Liu Yong, Zhao Fengwen, Zhang Chi, Zhang Jianming, Yang Weimin

Melt electrospinning is an even simpler and safer method compared with the
solution electrospinning in the production of ultra-fine fibers. Polylactic
acid (PLA) is a biodegradable and resorbable aliphatic ester that has
received significant attention in recent years. PLA is easily degradable at
high temperature in the process of melt electrospinning. High efficient
fibers were made using our designed umbrella-like spray head spinning
facility in this work. To find how to alleviate the problematic degradation
and what factors could be relevant to degradation, temperature, relative
molecular mass, Differential Scanning Calorimeter and X-ray Diffraction
patterns before and after spinning were investigated and compared with each
other. Results showed that fibers were facile shorten and fractured when spun
at 245°C while the relative molecular mass of PLA fibers decreased markedly
as compared with that spun at 210°C. To hinder the degradation, couple of
experimental efforts were implemented with adding antioxidants, raising
spinning voltage, lowering temperature, and reducing residence time. After
such efforts, it was observed that the relative molecular mass of the PLA
fibers was higher than those without inputting any efforts. The effect of
antioxidant 1010 was found the most promising on the alleviation of PLA
problematic thermal degradation.